function showLightBg(d_element){
                var $mdiv = $(d_element);
                d_id = $mdiv.attr("id");
                $mdiv.children(".t_bg").fadeIn(400);
            }
            
            function hideLightBg(d_element){
                
                var $mdiv = $(d_element);
                $mdiv.children(".t_bg").fadeOut(400);
            }